Connector fitting



Oct. 24, 1967 G. w. ZIEGLER, JR 3,349,166

CONNECTOR FI'.T."I'IIIG Filed Aug. 6, 1965 5 Sheets-Sheet 1 INVENTOR. I N, Game: WlLLmM'Zm-Lm,1-

\5 BY W Oct. 24, 1967 G w ZIEGLER, JR 3,349,166

CONNECTOR FITTING Filed Aug. 6, 1965 3 Sheets-Sheet 2 INVENTOR. GEORGE Wmmm ZlsoLea 5 CONNECTOR FITTING 6 Sheets-Sheet 3 Filed Aug. 6, 1965 INVENTOR. G-gozag WILLIAM ZIEGLERJJR.

BY M, 11M

United States Patent 3,349,166 CONNECTOR FITTING George William Ziegler, Jr., Carlisle, Pa., assignor to AMP Incorporated, Harrisburg, Pa. Filed Aug. 6, 1965, Ser. No. 477,899 11 Claims. (Cl. 174-88) This invention relates to fittings for terminals, connectors and splices of the type having requirements of close tolerance control and substantial mechanical strength.

In any high performance electrical connector there is a requirement for close tolerance control either to minimize electrical discontinuities and incidental mismatch or to provide a dimensional control for impedance compensation or adjustment. This control is achieved in the prior art through high cost production techniques and close inspection or it is not achieved with the result of poor performance or at least performance varying from unit to unit.

Most high performance terminals, splices and connectors have as an additional requirement, high mechanical strength in portions which, in an optimum configuration, include relatively thin 'wall sections. One of these is described in my co-epending application Ser. No. 308,265, filed September 11, 1963 and now U.S. Patent No. 3,245,027, granted Apr. 5, 1966. Virtually all high performance connectors and certain terminals and splices have a required capability of being mechanically and electrically engageable to some mating assembly. This is typically carried out in a connector structure by flanges, detents and the like, or by threaded or bayonet type fixtures secured to the forward end of the device. This type of structure entails a considerable amount of metal working with numerous secondary machining and milling operations being required.

The two design requirements of close tolerance and material hardness are not compatible with known high production volume techniques. This has generally lead to some sort of technical compromise which in turn has led to a product which is compromised in terms of mechanical strength and also in terms of electrical characteristics. For example, one approach of the prior art is to machine a given design out of solid stock brass material, which is thereafter hardened in some way. For many uses such as in my above-mentioned application, no practical treatment of such material can provide sufficient strength to thin wall sections which are necessary to maintain a constant impedance throughout the device. An alternative to this is to utilize thicker wall sections in treated brass parts with an overall larger diameter of the device resulting. This adversely affects size, Weight, and to an extent, cost through increased cost of material. More importantly, in the specific design referred to and in general, this approach very substantially increases the amount of force required to affect the termination of the connector to the cable of use. This, of course, increases tooling cost through an increase in tool size, and weight Another approach is to utilize a harder material such as beryllium copper and to machine the connector, terminal or splice device out of solid stock to the desired configuration. This is troublesome both in the length of time necessary to accomplish machining operations on hard material and in view of the fact that the outer and forward portions of the device need not have the characteristic of hardness called for in thin shell portions. Furthermore, in many standard fittings, such as in the threaded fitting or bayonet type fitting, extreme hardness of the material Works to a disadvantage; a softer material more readily permitting slight burrs and differences in part tolerances to be accommodated.

Accordingly, it is one object of the invention to provide a new fititng for terminals, connectors, splices and the like which combines the characteristics of material strength in certain portions and of workability in other portions of an integral assembly. It is another object of the invention to provide a fitting construction for terminals, connectors and splices which is less expenssive in terminals of cost of production for a given use requirement than heretofore available. It is still another object of the invention to provide a fitting construction for terminals, connectors and splices which has improved characteristics with respect to tolerance control and thus with respect to electrical characteristics and high performance electrical transmission. It is a still further object of the invention to provide a connector having :a smooth and even diameter of close tolerance extending along its length to serve as the outer conductive path for high frequency signal transmission provided in a relatively hard material of high yield strength with outer exterior portions in a softer material of characteristics desirable for intermating engagement.

The foregoing problems are overcome and the foregoing objectives are attained in the present invention through a structure useful in various terminal, connector and splice configurations, comprised essentially of met-allic tubing or rod of different material characteristics. In a preferred embodiment the metallic tubing includes a first piece of relatively thin, hard metal of high yield strength such as beryllium copper which is available as a member drawn to close tolerance and a second part which is of a softer, more workable material such as brass also available drawn to a relatively close tolerance. The hard part, by design, requires very little working and the softer part may readily be worked to the configuration required. The two parts are then assembled and brazed together to form the final configuration. With male and female configurations of such parts, a connector construction is provided having an internal bore of close tolerance extending fully therealong to serve as the outside conductive surface for high frequency transmission with the outer and softer portions being utilized to carry the structure for achieving engagement and disengagement for connector function. With parts constructed in accordance with the invention a terminal, connector or splice device is provided having a extremely thin wall section to serve as a back-up member for supporting ferrules, loading rings or the like employed to terminate a cable outer conductor to the device. The invention is particularly advantageous in use with smaller cable sizes where tolerance control becomes even more critical and with. L, T, or Y configurations where substantial machining is required.

In the drawings:

FIGURE 1 is a perspective of a connector for coaxial cable included to depict the type of device served by the invention;

FIGURE 2 is a longitudinal section of the connector of FIGURE 1 included to show and explain part of the problem solved by the invention;

FIGURE 3 is a longitudinal section of a connector in accordance with the invention but not terminated to cable;

FIGURE 4 is a perspective of the parts of FIGURE 3, somewhat reduced;

FIGURE 5 is a section of the material parts of the left half of the connector of FIGURE 3 prior to working and assembly;

FIGURE 6 is a longitudinal section of the parts of FIGURE 5 after working;

FIGURE 7 is a longitudinal section of the parts of FIGURE 6 after assembly;

FIGURE 8 is a perspective showing a right angle bend incorporating the invention; and

FIGURE 9 is a longitudinal section of the bend of FIGURE 8.

FIGURE 1 shows a connection mechanically and electrically joining the ends of coaxial cable through plug and jack halves forming a connector 10. The description hereinafter to follow of the invention in a preferred mode of practice will be devoted to this connector in terms of structure and function. It is contemplated, however, that the teachings herein given are fully applicable to terminal and splice structures and the references herein while drawn to only connectors, should be taken to embrace terminal and splice embodiments incorporating the invention. More specifically, the connector 10 in each half serves to mechanically and electrically terminate the ends of the cable 12 and it is contemplated that the part of the connector performing this function of termination can be embodied in devices which would qualify as terminals and have forward portions in terminal-like configurations. Further, the connector 10 could, in a splice configuration, be made integral by providing a continuous outer metallic member or, in fact, by welding or brazing the individual parts of the outer member if a disconnect function is not required. In T, L and Y configurations the advantages of the invention are particularly apparent, since the amount of working of the forward part of the device is realtively greater.

The invention will be described relative to a particular type of coaxial cable frequently utilized for high performance application wherein the signal energy transferred is in the microwave frequency range. It is contemplated that other and similar types of cable may also be readily served by the invention.

In FIGURES l and 2 the cable 12 is shown to include a center conductor 14 surrounded by a dielectric material 16 and an outer conductor 18. The center conductor 14 is typically of solid copper rod or hollow copper tubing coaxially supported by a dielectric material of foamed plastic, such as polypropylene within an outer conductor formed of aluminum tubing or copper sheathing. The conductors are made to have substantially smooth surfaces with an even and symmetrical configuration and the center conductor is exactly supported coaxially to maintain the spacing between its outer surface and the inner surface of the outer conductor along the length of the cable. The dimensions shown as D and d are carried throughout the length of the cable to a close tolerance. These cable requirements are necessary to achieve an efficient transfer of high frequency signals by eliminating zones of impedance 'mismatch and discontinuities which cause standing waves and signal reflections within the cable and resulting losses and degradation of the signals transmitted.

In high frequency applications the connector of use is typically specified in terms of tolerances and electrical characteristics to have a performance exceeding that of the cable electrically and mechanically in the hope that the connector device will at least equal in performance that of the cable. As the art is now developed, only a few connector designs actually meet the specifications laid down by industry. Most of these few are inordinately expensive, having a large number of parts and inherent design complexity calling for numerous changes in diameter and extremely close tolerances in both the metallic and dielectric material component parts.

Referring again to FIGURES 1 and 2, and considering for the moment the design there shown, which represents a simplification of connector structure with respect to other prior art, a few design problems will be briefly considered. For reasons which will become apparent hereinafter, the discussion and description of 10 will aid in an understanding of the invention. The connector 10 will be seen to be comprised of plug and jack halves, 20 and 40, which are identical in their outboard structure and similar in their inboard structure with a modification to provide mechanical and electrical engagement. Thus,

in half 20 there is an outer conductive sleeve member 22 relatively thick in wall section in its forward portion to include a flange 24 and beneath the flange a recess for engagement with the forward end of half 40. As an integral extension from 22, there is a further sleeve member portion 26 of relatively thin wall section ending in a bevel 27. The sleeve portion 26 serves as a back-up member to receive the cable outer conductor 18 and be terminated thereto mechanically and electrically through a loading ring 28 axially driven up over the outer conductor and 26 to a point of radial expansion and loading. A more complete description of this technique of termination is described in my co-pending application previously mentioned. To achieve the superior termination provided by this technique or even an adequate termination, the forces developed by the installation of 28 must be quite substantial and 26 must therefore be quite strong and rigid even though it is of thin wall section. In terms of material characteristics this means that 26 must be of a hard metallic material having high yield strength. This strength requirement for 26 would be true if the member 28 were a ferrule radially crimped against the cable outer conductor rather than axially driven thereon and it is contemplated that the invention is fully useful with crimp type connectors as well as the type employing the axial loading ring previously described.

It will be observed from FIGURE 2 that the interior bore of 22, including 26, is made to equal the inner diameter D of the cable and this represents a design approach which permits the connector to be employed if desired without adjustment or compensation of characteristic impedance; the maintenance of conductor spacing throughout the connector serving to maintain the connector characteristic impedance equal to that of the cable of use. If this diameter were larger or smaller than the diameter D of the cable then a discontinuity would be created, requiring either an adjustment of the connector design by a change in diameter of the inner conductor and/or the dielectric material between the conductive surfaces or requiring some type of compensation. For reasons which will hereinafter become apparent, structures requiring either an adjustment or compensation or both may employ the advantages of the invention. The reason for this is that with the design of FIGURE 2 or with designs requiring adjustment and/or compensation of characteristic impedance the starting point is always tied to a close control of tolerances; particularly the tolerance of D.

Fitted over the forward end of 22 and locked against displacement to the left by flange 24 is a nut 32 internally threaded at 33 to provide the connect-disconnect function for the connector and half 20. The half 44 includes a forward metallic sleeve member portion of relatively thick wall section 42, extending as at 44 for end-0n engagement with the forward end of 22 and externally threaded as at 45 to engage the threading 33 of nut 32. The rear portion of 40 includes an integral extension 46 of relatively thin wall section which serves as a back-up and termination structure for the outer conductor of the cable as locked thereto by a loading ring 48. The structure comprised of 46 and 48 is identical to that previously described with respect to half 20.

Each of the connector halves further includes a center contact member with the respective members 34 and 54 being shaped and adapted for an intermating fit. Each member includes a projecting portion such as 35 in member 34 which is threaded to be fitted into the cable center conductor 14. These members are carried to a diameter equal to d. After the connector halves have been terminated to the ends of the cables as shown in FIGURE 2, the connector device may be put together or taken apart to electrically and mechanically provide a connection of the signal paths represented by the cables. As can perhaps be appreciated the need for close tolerance control in the connector 10 is critical particularly with respect to the S internal bore of diameter D extending therethrough and the need for high strength of material is critical particularly with respect to the outboard sleeve extensions 26 and 46. As a matter of fact the forward and outer intermating portions of the connector halves should not be overly hard. This is because the surfaces thereof must intermate and any slight surface disparity which might prevent an easy threading of the members together of fitting of the forward ends should be capable of being accommodated. For example, burrs present on the threading or minute differences on the pitch of the threads would normally be eliminated in the first mating of the parts if the parts were of brass in almost any degree of hardness available. If the parts were of beryllium copper these same disparities would interfere with proper intermating.

With respect to 34 and 54 there is a requirement of hardness which, due to the sliding fit, does not cause problems in engagement but the requirement of tolerance control of these parts is also quite important. In the embodiment of FIGURE 2 these parts are usually machined out of solid beryllium copper rod.

Referring now to FIGURES 3 and 4, the invention improvement to the structure shown in FIGURE '2 is depicted with a part-by-part identity carried by the various numerals primed. The cable and locking rings shown in FIGURE 2 have been eliminated for clarity. A comparison of the devices of FIGURES 2 and 3 will show that the invention device is somewhat simplified in'terrns of both material, size and complexity of the various components. For reasons which will hereinafter be apparent, the connector represents a substantial improvement structually to that of FIGURE 2 and represents a substantial improvement in terms of mechanical and electrical function.

The connector half 20 is comprised of an assembly of a ring 22 and a metallic sleeve 26 brazed together as at 60. The ring 22' is adapted to receive a nut 32 which is locked against leftward axial displacement and is threaded as at 33', internally. The sleeve 26' is made to extend slightly forward of the ring 22' so as to fit within a portion of connector half 40'.

The half 40' includes a ring 42' assembled on sleeve 46' and brazed thereto as at 60. The forward portion of ring 42' carries threading to mate with 38. The forward end of 46' is set back from the end of the corresponding end of 42 as shown and the various rings are so arranged relative to the various sleeves such that when intermated the halves draw the ends of 26' and 46' together as shown. This means that the interior bore of the connector so formed is smooth and continuous along its length.

More important to the invention, the sleeves 26' and 46 consist of metallic tubing drawn to a close tolerance and having material characteristics of hardness and yield strength far in excess of the usual material for such structure. In an actual embodiment these sleeves were formed of beryllium copper tubing which is readily available at relatively low cost in tolerances to a 0.0005 of an inch with respect to the important dimension D. This contrasts with prior art approaches wherein solid rod would of necessity have been drilled out to provide the bore through the members. Those skilled in the art will readily appreciate the problem encountered with drilling out a structure of thin wall section to close tolerances, even in a material such as hard brass. The ring members 22' and 42' are also for-med out of metallic tubing which is available drawn to a fair tolerance at low cost. This material, in contrast with the sleeves 26 and 46' is made to be relatively soft, as for example out of brass. This means that engagement and disengagement of the parts even with fairly loose tolerances and the presence of surface disparities is readily accommodated by the inherent give of the material. This softer material is, however, supported substantially along its length by the harder sleeve members 26' and 46 to provide an overall rigidity with respect to maintenance of'dimensional integrity of the connector.

The connector assembly of the invention thus comprises a composite laminated structure having material characteristics of high yield strength and hardness in certain portions where necessary and having material characteristics of relative softness and machinability in other portions with an overall rigidity and adaptability to mechanical interfitting.

The center contact members 34' and 54' are formed of drawn rod and tubing of hard high yield strength material which is available to close tolerances at low cost. The member 34 includes an integral portion 35' which is machined from rod to include a forward projection 36 fitted into a sleeve 38' formed of tubing and soldered or brazed thereto. There is a slot in the sleeve which is not shown due to the view but is like that depicted in FIGURE 2. The member 54v includes a part 56' having a rear projection, threaded as shown, of solid rod which projects forwardly for engagement with 38. Around the rod is fitted a tube portion 58' which is soldered, brazed or otherwise secured thereto. These composite contact members do require machining but the machined portions are not critical either in terms of tolerance or mating engagement. The outer dimensions of the members forming the surface defining the dimension d are, however, left unmachined to the normal production tolerance of drawn tube or rod. The member 34' is made up in a similar manner which should be sufficiently apparent from the preceding description to enable its practice.

FIGURES 5, 6 and 7 show in further detail a preferred assembly for the connector of the invention. These figures relate to only the half 40' of the connector; the other half being omitted for simplicity but being assembled in substantially the same way. In FIGURE 5 two segments are shown in section representing drawn tubing readily available to close tolerance with respect to the diameter of the interior bores thereof. The tubing 46' is of hard, high yield strength material and the tubing 42 is of relatively soft material. FIGURE 5 also shows the parts for 54' prior to working including a rod segment 56' and a tubing segment 58'. As indicated in FIGURE 6 the only working of 46 required by the invention is that of the beveling of the outboard end as at 47. The tubing 42' is worked as indicated to provide threading and other features. Because of its relative softness the sleeve 42' may be very quickly and inexpensively machined. Since 42' is tubing it is unnecessary to machine the interior bore except to provide the bevel 60 at the outboard end which is preferred to accommodate a ring of brazing material slipped on 46 during the assembly of the two pieces. In practice the sleeve 46' may be inserted within 42' to the position shown in FIGURE 7 and a ring of brazing material slipped thereover into a position nesting within 60. Thereafter the sleeves may be brazed together by zone heating through induction at the site of the ring of brazing material. Care should be taken in this procedure to avoid annealing portions of 46'.

In practice it has been found desirable but not necessary to utilize beryllium copper for sleeve 46', which is, as purchased, half hard, and after the procedure indicated in FIGURE 7, heat treat the whole assembly for some time at 625 F. to thoroughly stress-relieve the composite structure and additionally harden the sleeve 46' to a full hard condition prior to overplating of the entire assembly for anti-corrosive and appearance purposes.

The invention connector thus represents a composite structure having characteristics of hardness and characteristics of softness where necessary and having close tolerance control where necessary all provided at low cost. The invention connector thus does not compromise mechanical strength and electrical characteristics as in the prior art.

The invention has been shown in a relatively simple structure comprised of a single sleeve of high yield strength and a single ring of relatively soft metallic material for one half. It is fully contemplated that the invention may be extended to other and more complex structures utilizing various assemblies of sleeves of hard material brazed or otherwise secured to rings or sleeves of soft material.

An example of this extension is shown in FIGURES 8 and 9 which represent a 90 angle connector. The connector 70 includes a forward heavily machined portion 72 which provides the angle and connector function. This member is not of tubing but rather machined out of solid stock, preferably hard brass or the like. To the rear portion of 72 is a hard sleeve 74 of the type described relative to parts 26' and 46 previously. The sleeve 74 is fitted into a recess 73 as shown and soldered, brazed or otherwise afiixed thereto. Thereafter necessary dielectric inserts are installed along with a center contact structure. It contemplated that the invention in this aspect can be readily extended to other angles, T, Y or various other configurations for connector devices. It is also contemplated that an additional sleeve 74 could be employed to make up a permanent right angle bend or splice.

The foregoing description has mentioned drawn tubing and such is preferred for reasons of strength, tolerance control and cost. It is contemplated that the term drawn material embraces both stock drawn tubing and pieces of the desired configuration in length and diameter individdually drawn.

Having now described my invention in a preferred mode of practice I now define it through the appended claims.

What is claimed is:

1. In a device for connecting coaxial cable of the type including a center conductor surrounded by a dielectric medium and an outer conductor having a given inner diameter held to a given close tolerance for efficient signal transfer, a first metallic sleeve of a material having relatively high yield strength, said sleeve having an outer diameter only slightly larger than the inner diameter of said cable outer conductor so as to be fitted within the outer conductor of the coaxial cable of use with a minimum enlargement and working of the cable outer conductor and having an inner diameter extending alongits length approximately equal to the inner diameter of the cable outer conductor and carried to a tolerance at least as close as the said given close tolerance of the inner diameter of the outer conductor of the cable of use, said sleeve having a configuration and strength characteristics to receive substantial radial forces applied thereto, a second sleeve positioned over said cable outer conductor and said first sleeve to apply substantial radial forces to terminate the cable outer conductor to said first sleeve through engagement with said outer conductor, a metallic member of relatively soft and easily machinable material fitted over a portion of said first sleeve and permanently afiixed thereto, said member having a surface configuration on the exterior thereof to provide a mechanical connection ofsaid device to other means.

2. The fitting of claim 1 wherein said member has an interior diameter defined by surfaces of drawn material.

3. In a device for connecting coaxial cable of the type including a center conductor surrounded by a dielectric medium and an outer conductor of a given inner diameter held to a given close tolerance for eflicient signal transfer, a composite structure including a first sleeve extending substantially along the length of the device, said sleeve being of a material of relatively hard and high yield strength and having a smooth bore therethrough of a diameter equal to the said given inner diameter of the outer conductor, said sleeve being adapted to be fitted beneath the outer conductor of cable and to receive and maintain its dimensional integrity against substantial radial forces compressing the outer conduct-or against the first sleeve outer surface, an exterior ring member forced over said outer conductor and first sleeve to develop substantial radial forces compressing the outer conductor against the first sleeve outer surface, a further member of metallic material substantially softer in material characteristics than that of said first sleeve positioned over a portion .of

said first sleeve and permanently affixed thereto, said further member including on its exterior surface means to provide an intermating fit with a complementary connector device.

4. In a device for connecting coaxial cable of the type including a center conductor surrounded by a dielectric medium and an outer conductor of a given inner diameter held to a given close tolerance for efficient signal transfer, a metallic sleeve of thin wall section of a material having a relatively high yield strength, said sleeve having an outer diameter to be fitted within the outer conductor of the coaxial cable of use and having an inner diameter extending along its length and equal to the inner diameter of the outer conductor of the cable of use, said sleeve having a configuration and strength characteristics to receive and support substantial radial forces applied thereto, means external of said device to terminate the cable outer conductor to the said device by forced engagement with said sleeve under substantial radial force, a metallic member of relatively soft and easily machinable material having an exterior configuration to provide a mechanical connection of said device to other means and having an interior bore carried to a diameter equal to the outer diameter of said sleeve to receive at least a portion of said sleeve inserted therewithin, the said sleeve and member being permanently afiixed together.

5. The fitting of claim 4 wherein the said sleeve in its configuration assembled within the said member has an insignificant portion of its exterior surface area deformed relative to its original state of forming and the said member has a substantial portion of its exterior surface deformed relative to its initial state of forming.

6. In a device for forming a mechanical and electrical connection with coaxial cable of the type having an inner conductor surrounded by dielectric material and an outer conductor, an integral structure including sleeve means of a material of high yield strength and of an outer diameter only slightly larger than the inner diameter of the cable outer conductor whereby to be fitted within the cable outer conductor with minimum deformation to said cable outer conductor as expanded by the said sleeve means, said sleeve means having a configuration and rigidity to receive and support substantial radial forces applied thereto, further sleeve means placed over the cable outer conductor and driven to compress portions of the outer conductor in against the exterior surface of said first mentioned sleeve means to form a stable interface therewith, further means of metallic material and of relatively thick wall section extending over a portion of said first mentioned sleeve means and radially outwardly thereof, said further means including means to lock said device mechanically and electrically to other means, the said further means having material characteristics substantially softer than that of the said sleeve means.

7. The fitting of claim 6 wherein the said sleeve means is comprised of drawn tubing having characteristics of yield strength on the order of beryllium copper and the further member is comprised of conductive material having characteristics of hardness on the order of brass.

8. In a connector or splice device for coaxial cable of the type having a center conductor surrounded by dielectric material and an outer conductor of a given inner diameter held to close tolerance for efficient signal transfer, a sleeve means of relatively thin wall section formed of material of high yield strength, the said sleeve means having an exterior diameter onlyslightly larger than the given innerdiarneter of the outer conductor so as to be relatively easily fitted within the outer conductor of the cable of use and having an inner diameter along its length equal to the inner diameter of the outer conductor and formed to an accuracy of tolerance approximately equal to the said given tolerance of the inner diameter of the outer conductor of the cable of use, the said sleeve means extending for the full length of said device and adapted to J be fitted within at least :two vends ,of said cable, further means fitted over portions of said sleeve means to provide a mechanical interconnection of the two ends of said cable, said further means being of metallic material substantially softer than that of said sleeve means.

9. The device of claim 8 wherein the said further means includes in its forward portion surfaces adapted for intermating and said sleeve means is comprised of at least two sleeves locked together by said further means.

10. In a device for interconnecting coaxial cable of the type having a center conductor of a given outer diameter surrounded by a dielectric material and an outer conductor of a given inner diameter, the said given outer and inner diameters being held to a close tolerance along said cable for eflicient signal transfer, an outer conductive means adapted to be connected to the cable outer conductor and an inner conductive means adapted to be connected to the cable inner conductor, the said outer conductive means being comprised of a thin wall metallic sleeve of a diameter to 'be inserted Within the cable outer conductor and of material having a relatively high yield strength having an inner diameter equal to said given inner diameter of the outer conductor and being adapted to be fitted within the said outer conductor, and means for forcing the outer conductor against said sleeve under substantial radial force, said sleeve having affixed thereto and fitted over a portion thereof a further metallic member of relatively soft and easily machinable material to provide a mechanical connection of said device to other means, said inner conductive means being comprised of relatively hard conductive material drawn to a diameter equal to the given outer diameter of the inner conductor and carried to a tolerance approximately equal to the given tolerance of the inner conductor of the cable.

11. The device of claim 10 wherein said inner conductive means includes at least one member formed of drawn rod material and one member formed of drawn tubular material, the said two members being permanently aflixed together.

References Cited UNITED STATES PATENTS 2,250,286 7/1941 White 285256 2,434,509 1/1948 Okress 333-97 2,497,706 2/1950 Wetherill 17489 X 2,536,003 12/ 1950 Dupre 17488 .2 2,878,458 3/1959 Jackson 339177 2,926,029 2/ 1960 St. Clair et al 285256 3,245,027 4/1966 Ziegler 17488 X DARRELL L. CLAY, Primary Examiner. L. H. MYERS, Examiner. 

1. IN A DEVICE FOR CONNECTING COAXIAL CABLE OF THE TYPE INCLUDING A CENTER CONDUCTOR SURROUNDED BY A DIELECTRIC MEDIUM AND AN OUTER CONDUCTOR HAVING A GIVEN INNER DIAMETER HELD TO A GIVEN CLOSE TOLERANCE FOR EFFICIENT SIGNAL TRANSFER, A FIRST METALLIC SLEEVE OF A MATERIAL HAVING RELATIVELY HIGH YIELD STRENGTH, SAID SLEEVE HAVING AN OUTER DIAMETER ONLY SLIGHTLY LARGER THAN THE INNER DIAMETER OF SAID CABLE OUTER CONDUCTOR SO AS TO BE FITTED WITHIN THE OUTER CONDUCTOR OF THE COAXIAL CABLE OF USE WITH A MINIMUM ENLARGEMENT AND WORKING OF THE CABLE OUTER CONDUCTOR AND HAVING AN INNER DIAMETER EXTENDING ALONG ITS LENGTH APPROXIMATELY EQUAL TO THE INNER DIAMETER OF THE CABLE OUTER CONDUCTOR AND CARRIED TO A TOLERANCE AT LEAST AS CLOSE AS THE SAID GIVEN CLOSE TOLERANCE OF THE INNER DIAMETER OF THE OUTER CONDUCTOR OF THE CABLE OF USE, SAID SLEEVE HAVING A 